Metal-screw machine



(ModeL) 4 Sheets-Sheet 1. A. JOHNSTON.

Metal Screw Machine.

No. 269,791. Patented Dec. 26,1882.

Mil

(ModeL) 4 Sheets-Sheet 2.

A. JOHNSTON.-

Metal Screw Machine.

No. 269,791. Patented'De0.Z6, 1882.

WITNESS EE (ModeL) 4 Sheets-Sheet 3.

. A. JOHNSTON. Metal Screw Machine.

No. 269,791. Patented Deo.26,1882.

(ModeL) 4 Sheets-Sheet 4. A. J O H N S T O N.

Metal Screw Machine.

No. 269,791. Patented Deo.2.6,1882.

I mounted, so that by turning the turret the changed, as in theturret-machines, but are al- I UNtTtE STATES IATENT truce.

ALLEN JOHNSTON, 0F o'rTUMWA, IOWA.

METAL-SCREW MACHINE.

SPECIFICATION formingpart of Letters Patent No. 269,791, dated December26, 1882,

Application filed October 22, 1880.

To all whom it may concern Be it known tltat I, ALLEN JOHNSTON, 0t()ttnmwa, in the county of Wapello, in the State of Iowa, have inventedcertain new and useful lmprovementsin Metal-Screw Machines, of which thefollowing is a specification.

My invention relates to automatic machines for making screws, rivets,and other like turned articles from the. end of a rod or wire.

Heretot'ore such machines have usually been constructed with a revolvingturret, in which the several screw-forming tools have been several toolscould be presented in turn to the end of the rod. In some machines,however, the chuck and the tools have been combined with slides orreciprocating supports, so that the tools do not have their directionconstantly ways maintained parallel with the axis of the chuck, and aresuccessively brought in line with it by back and forth movements acrossthe said axis. The. invention has reference more particularly to thisclass of machines, although in part not limited thereto.

It consists, first, in the combination, with the chuck, the series oftnrning-tools-such as the milling, threading, and cutting-oil tools andthe longitudinally and laterally movable slides or reciprocatorysupports, of a continuously-revolving cam and mechanism operated by saidcam for imparting to said slides or supports the requisite lateral andlongitudinal movements. Others have operated similar slides or supportsby hand or from a cam to which an intermittentrotation is imparted.These dispositions are not within this first part of the invention. Byso constructing and combining the parts that: the cam may revolvecontinuously the complicated mechanism used to give an' intermittentrotation to the cam is dispensed with and the advantages of an automaticmachine are attained, while at the same time the machine is renderedmuch more simple, ctficient, and durable.

The invention secondly consists in the combination with the chuck, thetnrning-dovtn or millingtool,thethreading-tool,thelongitudinal and crossslides, and the means for shifting the Citadel.)

' I cross-slide back and forth, of automatic mecln anism-such as a camand connections-for positively advancing the longitudinal slide, as wellin the threading as in the turning-down or milling operation, and forcontrolling the return of the same when each operation is completed.This combination should be distinguished from one in which thethreadingtool, without the longitudinal slide, is drawn forward by theaction of the newly-termed thread upon the die, the latter combinationbeing notincluded by this portion of the invention.

The invention thirdly consists in the combination, with the longitudinalslide, the chuck, and the tools, of a cross-slide and slide-shiftingmeans, operating through the reciprocation of said longitudinal slide,for shifting said cross-slide back and forth, so as to present the toolssuccessively in line with the axis of the chuck. The said shifting meansare herein shown as a peculiar-shaped cam and its connections, and willbe hereinafter particularly described.

The fourth part of the invention consists in the combination of a hollowchuck-spindle, the chuck carried thereby, means for opening and closingthe jaws of said chuck, a longitudinal slide, a cross-slide, aturning-down 'or milling tool, a threading-tool, and a lengthgage. v

The invention further comprises the particular new constructions andcombinations of parts hereinafter specified.

-In the accompanying drawings, which form a part of this specification,Figure 1 is a. plan of my improved machine. Fig. 2 is a central verticallongitudinal section of the same. Fig. 3 is an elevation of a cam-wheel,hereinafter to be described. Figs. 4, 6,7, 10,11, and 12 are verticaltransverse sections taken on the lines 4, 6, 7,10, 11, and 12 of Fig. 2,respectively. Fig. 12 is enlarged. Fig. 5 is a horizontal section online 5 of Fig. 2. Fig. 8 is a central vertical longitudinal section ofthe cutting-01f tool in detail and enlarged; and Fig. 9 is a horizontalsection of the same, taken on line 9 of Fig. 8. Fig. 13 is alongitudinal section of the chuck, taken on line 13 of Fig. 12; and

Fig. 14 is an enlarged perspective in detail of the bed-piece andrecessed cam which gives the lateral motion to the sliding tool-holder.

1n the drawings similar letters of reference indicate like partswherever used.

()u said drawings, A represents the frame of the machine; and B is themain shalt, mounted in suitable bearings,B,iu the frame, and driveu fromthe chnck spindle C through the iiitermediate gear-wheels, b, I), 0 b1), b b and I)", meshing with each other. The gearings b and I) turn onthe noirrevolving shaft 0,:lnd the gearings and l) are keyed toshoulders on the gearings b and b, respectively; and the gearing b iskeyed to a like shoulder on gearing I), which turns on the main shaft B,to which the gearing b is keyed. The purpose of this system of geariugsis to reduce the motion of the main shaft B. which carries the cams foractuating the different parts of the machine.

The hollow spindle O is mounted in suitable bearings, U, and derives itsmotion from the driving-pulley C and the reversing-pulley the former ofwhich is made of several sizes. Both these pulleys fit loosely on thespindle, and each in turn is connrcted with the spindle, so as toactuate it by means of the connecting-pins d and d, which lit loosely inradial holes in the spindle and in the fixed heel D, secured thereto,and are pressed out from the center and against the interiorcircninlerence of the pulleys by the double cone-slide E, upon which theinner ends of the pins rest. The slide E is secured to or forms the endof the tube 0, which fits loosely ill the hollow spindle, and the slideis actuated by means of the lever e, pivoted to the frame, and the camsf and f, bolted to the cam-wheel F, which is keyed to the main shaft.The upper end of the lever e is forked, and fits in a collar secured tothe end of the tube a.

Gr represents a portion of the rod or wire from which the screw or otherarticle is to be formed, and it is gripped firmly and caused to revolvewith the spindle by means of the chuck secured to the end of thespindle.

The chuck consists of the part-way split tube H, having a conicalexterior and hollowed out ath, for the purpose of giving elasticity tothe split portions which form thejaws h, for gripping the rod or wire.The tube H is secured by means of screw-threads to the hollow sleeve H,which itself is screwed to the end of the spindle U.

Thejaws h are compressed so as to grip the rod or wire by means of theconical wedges h consisting of a hollow cylinder split in two parts,having a conical interior to conform to the conical exterior of thejawsh. The wedges h are connected with the collar h by means of the pins orscrews h, and are actuated by means of the spiral springs h one end ofsaid springs titting in recesses in the collar h and their other ends inlike recesses in the sleeve H. The pins h work in longitudinal slots Itin the sleeve B when the collar is pressed forward or back. The collar his pressed forward, so as to compress the springs and open the jaws ofthe chuck to feed forward the rod, by means of the forked lever It,pivoted to the frame at [08, and carrying conical friction-rolls h whichtit against the conical end h of the collar. This lever is actuated atproper iiitervals by the cam h, which is keyed to the main shaft. Therod G is pushed or fed forward when the jaws of the clutch are relievedfrom the pressure of the springs by means of a following-rod (not shownin the drawings,) impelled forward in the tube 0 and hollow spindle bythe pulley and weight I. l is a portion of the tube in which thisfollowing-rod is supported.

J is the cross-slide or sliding tool-holder, mounted on the longitudinalslide K in a transverse groove, K, so that it may be shifted laterallytherein for the purpose of bringing the difl'erent screw-forming toolsin position for work. The said cross'slide or sliding toolholder isprovided with a numbor of holes or mortises, 7'. in its front face forthe insertion ofthe screw-formingtools; andj are set-screws for thepurpose of securing and adjusting the said tools in position. Thedrawings show only three such inortises; but any number desired maybeprovided. The sliding tool-holder is alternately adwancedand drawn backby means of the cylindrical grooved cam L, keyed to the main shaft,operating upon a pin, l, secured to the slide K. The pin 1 works backand forth in a slot, 1, in the bed-piece M, which is bolted seenrely tothe frame of the machine, and the sliding tool-holder is at the sametime shifted laterally by means of the recessed cam m,cut in thebed-piece, operating upon a. spring-pin, M, the lower end of whichproiectsdown through a transverse slot in the. slide K and tits in thecam m. The form of the cam m is shown in the perspective view, Fig. 14,and consists in agroove returning into itself and having as many frontprongs or ways, on", as there are tools on the tool-holder. The depth ofthis groove at different points is such thatjust before entering each ofthe ways at the pin m will rise gradually and drop over an abrupt ledge,which is curved so as to guide the pin into the next way m when thetool-holder is drawn back, thus preventing the pin returning backward inthe same path and causing it to enter each of the ways at in succession,and tinally to return to its startingpoint, when the same operation isrepeated again and again. The engagement of the pin in the ways induring the operation of the tools prevents lateral motion and holds thetool in line. The pin m is provided with a spring, at, to allow it toaccommodate itself to the varying depth of the groove or cam.

Of course other equivalent means may be employed for comm unicatiug tothe tool-holder its lateral and longitudinal motions, and I do not wishto confine mysell'to the specific means seat o:

shown. I, however, prefer the means described, consisting of the cams Land in, as being the best method of practicing my invention.

Instead of shifting the tool-holder transversely by means of the cam on,its transverse motion may be imparted to it directly from the main shaftby a suitable cam thereon and connecting-lever, or other equivalentmeans.

N is the shaft or spindle, in the end of which the thread-cutting dies aare secured by means of the conical screw-sleeve n. The spindleN ismounted in a sleeve, 12?, inserted in one of the hole'sj in thetool-holder, and is provided with a spring clutch or pin, a, whichengages in a longitudinal clutch or groove, a iii sleeve a so as topermit the spindle to revolve in one direction, but not in the other.The purpose of this clutch a n is to prevent the spindle N fromrevolving, when the clutch is reversed in order to unthread and withdrawthe die from the screw; and the front end of the sleeve a and theshoulder a of the spindle N are so shaped as to form a clutch, a toprevent the spindle N from revolving while the die is cutting thethread. By this arrangement the die-spindleN hasa free longitudinalmotion independent of the sliding tool-holder, so that when the advance.movement ofthe sliding tool-holder is stopped a little before thecutting of the thread is completed the die will continue to cut andthread the screw and the spindle N to advance until the two parts of theclutch a are disengaged, when the die will revolve freely with thechuck, as the clutch n n offers no obstruction to its revolution in thisdirection and when the chuck is reversed to unthread the die from thescrew, as the die-spindle has a free longitudinal motion independentofthe backward motion of the tool-holder, the die automaticallyaccommodates its retracting motion to the number of threads on the screwand the velocity of revoluti n of the chuck. For this reason,

though the driving-pulleys are of several dif i'erent sizes, thereversing-pulley need be of but one size, and much less nicety isrequired in constructing and adjustingthe cam which draws back thetool-holder, whereby much difficulty and trouble are avoided, as well asdanger ofjamtning and injuring the thread for lack of proper adjustment.

The shank l of the cutting-off tool is adjusted and secured in one ofthe holesj of the tool-holder, and is provided with a head, P, carryingthe vertical slidep, to which the knife 11 is secured. After theknife 1) is brought into position by motion of the sliding toolholder,the slide p is pushed up vertically, carrying the point of the knife 1)across the axis of the revolving rod or wire, thus severing the screwtherefrom by means of the rod 1), actuated by the peripheral cam 19 onthe main shaft. The rod 19 works up and down in a hole or hearing in theframe of the machine, and is provided with a spring, 12 to regulate andsteady its motion, and carries a frictionroller, 19 at its lower end.The elongated portion of the cam 12 pushes the rod 19 up in front of therod or wire G after the cutting-off tool has been retracted, so that itsflat front face will serve as a stop or feed-regulating tool for the rodG when the chuck is opened, so as to allow the same to be pushed forwardbythe weight. y i

The shouldering or turning-down tool Q is of the ordinary construction,and is mounted parallel to the other tools in the sliding toolholder. Astop or feed regulating tool may be mounted in the sliding tool-holder,if desired or preferred, and my improved machine may be used with othercutting-011' and threadforming tools than those herein described.

Besides screws, my machine is also adapted to form rivets and other likearticles by substitutingthereqnisite forming-tools in the toolholder.

The operation of my improved machine is as follows: The rod G beinggripped in position for forming a screw by the chuck, and the machinebeing set in motion, the cam L causes the sliding tool-holder toadvance, presenting the turning-down tool Q to the end of the revolvingrod, the tool Q continuing to advance with the sliding tool holder untilit has done its work, when the cam L causes the tool-holder to recedeand to again advance, while at the same time the cam in causes thetool-holder tomove laterally on the longitudinal slide K, so as thistime to present the thread-cutting tool to the end of the rod. After thethread is cut, the instant the clutch 12 becomes disengaged in themanner already described, so as to permit the die to revolve with thechuck, the cam L causes the tool holder to recede a distance about equalto the length of the screw to be cut, at which point the cam-wheel Fmoves the conical slide 15 and reverses the motion ofthe chuck, and thusunthreads the die from the screw. The tool holder recedes and againcomes forward, this time bringing into position the cutting-off tool. Assoon as the tool-holder stops the cam p pushes up the slide and carriesthe knife across the axis of the rod, thus severing the screw from therod, when the'toolholder again recedes into its original position, whileat the same time the stopping-tool is pushed up in front of the rod G bythe elongated part of the cam p and at the same time the cam It opensthejaws of the chuck, permitting the tollowing-rod, actuated by theweight, to shove the rod Gr forward against the stopping-tool, thusgaging the length necessary for the next screw, when thejaws ofthe chuckagain grip the rod, and the stoppingtool is withdrawn out of the way,and then the operation is repeated, as before.

The forms of the several cams described and their relative position onthe main shaft B are such as .to actuate the several devices and producetheir operations in the manner and order described.

\Vhat I claim is 1. The combination, with the chuck, the series oftools. the longitudinal and cross slides, and the mechanism tor shiftingthe cross-slide back and l'orth, of the revolving'cam for recip rocatingthe longitudinal slide and the mechanism for imparting continuousrotation thereto, substantially as described.

2. The combination, with the chuck, the turning-down tool, thethreading-tool, thelongitudinal slide, the cross-slide, and theautomatic means for shifting, said cross-slide back and forth, of theautomatic mechanism for advancing the longitudinal slide, as well inthreading as in turning down, and for returning the said slide,substantially as described.

3. The combination, with the chuck, the turning-tools. the longitudinalslide, and the cross-slide, of the shifting mechanism operated by thereciprocation of sail longitudinal slide for shifting the cross-slideback and forth to present the tools successively in line with the axisof the chuck, substantially as described.

4. The combination, with the chuck, the means for opening and closingthejaws otsaid chuck. the longitudinal slide, the cross-slide, theturning-down or milling tool, the threading-tool, and the lengthgage,substantially as described.

5. The combination. with the chuck, the longitudinal slide, thecross-slide, the turningdown or milling, tool, the threading-tool, thelength-gage, and the cutting-off tool, of automatic mechanism-such asthe cams and connections-tor opening and closing the chuckjaws and forbringing said tools into action, substantially as described.

6. 'llhecombination,withthemachine-frame, the chuck, and the length-gagesupported by a stationary part of the machine and movable across theaxis of the chuck. ot' the automatic mechanism for relieving andrestoring, the bite ofthechuck-jawsand foroperatingsaid lengthgagre,substantially as described.

7. The combination, with a tool-holder and mechanism for impar inglongitudinal and lateral motion thereto, of a pin and a series of waysor grooves arranged, as indicated, so as to prevent lateral motion ofthe tool-holder during the operation of the tools mounted thereon,substantially as described.

8. The combination of a revolving chuck, a series of tools mounted onthe tool-holder J, slide K, tool-holder J, mounted on said slide, andcams L and m, substantially as described.

9. The combination of the tool-holder with the spindle for thethread-cutting die, and clutch n 'n to hold said spindlefor the purposeof unthreading the die from the screw and at the same time permit a freelongitudinal m0- tion of the die-spindle independent of the motion ofthe tool-holder as it is Withdrawn without disengagement of said chuck,substantially as described.

10. The recessed cam m, arranged and const ncted, substantially asdescribed, to permit an al ernately advancing and retreating motion tothe tool-holder, in combination with the sliding, toOHlOltlQI,substantially as set forth.

11. The combination of the tool-holder, slide K, pin m, and cams L andm, substantially as described.

12. Thecombinationot' the chuck, tool-holder, cutting-off tool carriedby said tool-holder, knife-carrying slide, rod 1), and cam 1),substantially as described.

13. The combination of the hollow chuckspindle, the driving andreversing pulleys, connecting-pins, double cone-slide E, tube 6, locatedinside of said spindle, and actuating canrwheel F, substantially asdescribed.

14 Thecombinationoftheconicaljaws,made in one tubular piece split back aportion ofits length, with the cylindrical exteriorly-conicalinteriorly-splitsleeve, collar h, pins h, springs If, and cam and leverfor actuating the chuck, substantially as described.

ALLEN JOHNSTON.

Witnesses J. M. MURRAY, EDMUND AnsAK.

